Native to eastern North America, Black haw is a deciduous shrub with white flowers and shiny, juicy, blue-black berries. As a matter of fact, the root bark and extracts of this shrub are both used to make medicine. Due to the fact that black haw contains a chemical that might relax the uterus, its ethnobotanical uses include treatment of female reproductive complaints. It is also used to increase urine (as a diuretic) to relieve fluid retention; and to treat diarrhea, spasms, and asthma. Even though black haw has historically been used to prevent abortion and miscarriage, it is still not clear whether this shrub is safe to use during pregnancy and breastfeeding. Like many other plants, including many food plants and those used as culinary herbs, black haw contains salicin, a chemical relative of aspirin. Those who are allergic to that substance should not use this plant. In addition, due to the connection between aspirin and Reye syndrome, young people or people afflicted with a viral disease should not use it, too.